Using underwater speakers to play noise at levels similar to those
produced by recreational speedboats, the researchers found that three-spined
sticklebacks exposed to even brief noise playback made more foraging
mistakes and were less efficient at consuming the available food
compared to those in quiet conditions.

Dr. Julia Purser, the study's lead author, said: "The fish appeared
to be distracted by the addition of noise to their environment. Much as
you or I might struggle to concentrate on a difficult assignment when
faced with loud construction noise, these stickleback seemed unable to
keep their mind fully on the job at hand, attending to random items of
tank debris and mishandling food items more frequently when noise was
played."

While they did not abandon feeding behaviour entirely, as you might
expect under stressful conditions, the fish were certainly less accurate
and efficient in their feeding efforts during noisy conditions, even
when the noise exposure lasted as little as ten seconds.

The foraging mistakes are consistent with a shift in attention when
exposed to noise, and in the natural environment these mistakes could be
costly: increasing the chances of ingesting harmful items, and affecting
the risk of predation if fish have to forage for longer to compensate
for reduced efficiency.

In many aquatic environments, noise pollution will often continue for
much longer periods than the exposures used in this study, or occur
repeatedly, and so the research team, led by Dr. Andy Radford, are now
examining how the fish may adjust with exposure to repeated or chronic
noise.

Dr. Purser continued: "In terms of recognising and managing the
impact of noise pollution on the aquatic environment, this study
illustrates the importance of not only looking for the more obvious
immediate effects of noise, such as hearing deficits and dramatic
behavioral changes associated with stress, but also examining the more
subtle but nonetheless important and potentially damaging impacts on the
everyday behaviour of animals."Co-author Dr Andy Radford, who leads a
major project to investigate the impact of anthropogenic noise on marine
animals, said: "Noise pollution is a rapidly increasing issue of global
concern, especially underwater.

Although lots of research has considered the potential impacts on
marine mammals, we know relatively little about how fish are affected,
despite their critical importance as a food source for the burgeoning
human population. Our study suggests there could be a much wider range
of detrimental effects than previously thought, and so there is a vital
need for further research.